In May 1989, Lisle Corporation (Lisle) (plaintiff) began developing a tool intended to make automobile steering control repair more efficient. On December 12, 1989, Lisle delivered a prototype of the tool to four repair shops. Lisle did not collect payment for the prototypes, nor did Lisle require the mechanics to execute formal confidentiality agreements. According to company protocol, however, Lisle contacted the mechanics regularly to receive testing feedback. Lisle filed a patent application for the tool on June 26, 1992. In 2002, Lisle brought a patent infringement suit against A.J. Manufacturing Company (A.J.) (defendant). A.J. argued the patent was invalid under the 35 U.S.C. § 102(b) public use bar. At trial, Daniel Williams, co-inventor of the tool, testified that Lisle distributed the prototypes to the mechanics because the inventors needed to test how the tool fit into the tie rods of different automobile models. Williams further testified that he modified the tool’s design based on mechanic feedback, and that though no formal agreements were signed, Lisle maintained prior working relationships with each mechanic. Williams also testified that he believed the mechanics knew the prototype was given to them for testing purposes. A jury concluded that the patent was not invalid under the public use bar. The district court denied A.J.’s motion for judgment as a matter of law. A.J. appealed.